This innovation originates from the constant improvement searched on grain seeding machines, particularly, those used for so-called direct seeding or no-till seeding.
Moreover, Argentinean registrations of Invention Patents, belonging to the firm named Avec S.R.L, such as:
No. 247466—Dispositivo óleo—neumático de control de cargas (Oil pneumatic load control device)
No. 249176—Mejoras en un dispositivo óleo—neumático de control de cargas (Improvements on an oil-pneumatic load control device)
No. 250967—Conjunto articular de brazo principal y balancín (Joint assembly of main arm and balance beam)
are the background based on which, upon constant operation development and improvement, the present innovation is produced.
The Oil-pneumatic Load Control Device, together with the Balance Beam System, provides exact regulation of the preset loads based on the soil to be seeded. The loads are therefore kept constant at all times, regardless of the unevenness of the soil. Therefore, a constant load combined with the perfect tracing of the soil guarantees uniformity in seeding depth followed by the appropriate covering.
The problem associated to this study is a result of the obstruction with vegetable residues, dust or moist soil, which enter between some of the components of the so called “seeding assembly” or “seeding train”.
The development of this invention is inspired on the arrangement of the known seeding assembly elements, the fact that said assemblies are rigidly conformed, and the poor adaptability for their self cleaning or evacuation of the vegetable residues, dust, etc. One object of this invention is to improve adaptability of the assembly, achieve an easy and correct evacuation of the accumulated residues and provide the user of the seeder higher effectiveness, work efficiency, and most importantly, the minimization of detention time caused by obstruction of the seeding assembly.
Generally seeding assemblies include the following:                a) A device to open the furrow, usually composed of one or two flat disks 1 (single disk, double disk), mounted with a certain inclination in relation to vertical and horizontal planes, which allows them to perform such task, or composed of a kind of spike or hoe (not shown) (see FIG. 1);        b) A device to place the seed from a storage hopper (not shown) to the bottom of the furrow, generally consisting of a flexible tube (not shown) connected to a rigid tube 2 placed between both disks or on the side of the single disk;        c) A device to place fertilizer from a storage hopper (not shown) to the bottom of the furrow, generally consisting of a flexible tube (not shown) connected to a rigid tube 3 placed between both disks or at the side of the single disk (this is what commonly occurs when fertilization and seeding take place simultaneously).        d) A device to control depth of the seed in the furrow; this may be carried out by rings laterally attached to one of the furrow disks (or to the single disk) (not shown), or either by one or two wheels with rubber tires 4 indicated on FIG. 1; in the case of rings, the different depths are regulated by varying the size (diameter) of the rings; whereas in the case of wheel(s) there is a specifically designed mechanism 5 for said regulation of depth, for example the one indicated on FIG. 1;        e) A device to close the furrow, which usually consists of one or two wheels with rubber tires 6; to which serrated disks are normally attached;        f) There are some designs which also include a device which presses the seed against the furrow walls, after said seed has been placed therein and before closing the furrow; generally said device is a metal wheel 7 or it includes a rubber or plastic tire.        
The above mentioned elements from a) to f) are well known in the previous art and can have different designs, therefore any constructive details about them will be given. They are usually placed on a so called balance beam 8 on the present invention and on the above mentioned Argentinean patents, generally a straight one, ordered in such a way that they operate with the correspondent sequence (furrow opening up to certain depth; placing of the seed and fertilizer; seed pressing; furrow closing).